Abstract
Among terrestrial enchytraeid oligochaetes, species of the genus Achaeta are conspicuous by their complete absence of chaetae. Knowledge of Achaeta species in South America is scarce, only four species were known so far. Here we describe three more species of Achaeta from South America, A. hanagarthi, A. paranensis and A. singularis spp. nov., and we provide revised and type-based redescriptions of A. neotropica Č ernosvitov, 1937 and A. piti Bittencourt, 1974. The species were found in the framework of the German-Brazilian project " SOLOBIOMA, Soil biota and biogeochemistry in the Atlantic rainforest of Brazil", which monitors forest regeneration on previously degraded areas by comparing successional stages from pastures to old-growth forests. Species descriptions are based on observations of specimens in vivo and as stained whole mounts; special attention is given to variations among specimens. The three new species are ascribed to a single author (Schmelz). They lack pyriform glands and have spermathecal ectal pores in lateral position. Further distinguishing traits concern the location of preclitellar nephridia, coelomocyte texture, distribution pattern of epidermal and clitellar gland cells, and the inner topography of the prostomium, the latter a new character in Achaeta taxonomy. In A. hanagarthi all sexual organs except the spermathecae are shifted one segment forward. A. singularis is most peculiar by a short and deeply incised brain and by the apparent absence of a suboesophageal ganglion, the ventral ganglia of segments II, III, and IV being separate. This species was only found in forests and is possibly a true representative of the old autochthonous forest soil fauna. A. hanagarthi and A. singularis are similar to the ill-described A. silvatica Nurminen, 1973; the latter is considered as a species inquirenda here. Type reinvestigations revealed that contrary to the original descriptions, A. piti has six segmental pyriform glands and reproductive organs except spermathecae shifted one segment forward, and that A. neotropica has the first preclitellar nephridium at 6/7 and ectal spermathecal pores inlateral position. A. neotropica is highly variable and probably a species aggregate, difficult to resolve with traditional light-microscopical methods. The recently described A. becki Schmelz & Collado 2005 is tentatively included in A. neotropica. The taxonomic descriptions contribute to the general anatomy of the genus; our study further serves as a guide to neotropical species of Achaeta.References
Beck, L. & Höfer, W. (2003) Dr. Werner Arthur Hanagarth † 1948 – 2003. carolinea, 61, 235–240.
Bihn, J.H., Verhaagh, M., Brändle, M. & Brandl, R. (2008) Do secondary forests act as refuges of old growth forest animals? Recovery of ant diversity in the Atlantic forest of Brazil. Biological Conservation, 141, 733–743.
Bittencourt, E. (1974) Algumas Enchytraeidae (Oligochaeta) de Sâo Paulo. Revista Brasileira de Biologia. Rio de Janeiro, 34, 369–378.
Černosvitov, L. (1937) Notes sur les Oligochaeta (Naididées et Enchytraeidées) de l'Argentine. Anales del Museo Argentino de Ciencias Naturales, Buenos Aires, 39, 135–157.
Chalupský, J. (1992) Terrestrial Enchytraeidae (Oligochaeta) and Parergodrilidae (Polychaeta) from Sweden, with description of a new enchytraeid species. Zoologica Scripta, 21, 133–150.
Christensen, B. & Dózsa-Farkas, K. (1999) The enchytraeid fauna of the Palearctic tundra (Oligochaeta, Enchytraeidae). The Royal Danish Academy of Sciences and Letters, Biologiske Skrifter, 52, 1–37.
Christensen, B. & Dózsa-Farkas, K. (2007) Achaeta pigmentosa sp. n. from Borneo - with dorsal pores (Enchytraeidae, Oligochaeta). Folia Facultatis scientiarum naturalium Universitatis Masarykianae Brunensis, Biologia, 110, 41–51.
Christoffersen, M.L. (1979) Achaeta neotropica Cernosvitov and A. iridescens sp. n. (Oligochaeta, Enchytraeidae) from Serra do Mar, Sâo Paulo, Brazil. Zoologica Scripta, 8, 153–158.
Coates, K.A. (1989) Phylogeny and origins of Enchytraeidae. Hydrobiologia, 180, 17–33.
Collado, R., Martínez-Ansemil, E. & Giani, N. (1993) Les Oligochètes aquatiques de la Péninsule Ibérique: description de Stylodrilus curvithecus n.sp. (Lumbriculidae) et de Mesenchytraeus lusitanicus n. sp. et redescription de Cognettia hibernica Healy (Enchytraeidae). Annales de Limnologie, Toulouse, 29, 129–138.
De Wit, P. & Erséus, C. (2007) Seven new species of Grania (Annelida: Clitellata: Enchytraeidae) from New Caledonia, South Pacific Ocean. Zootaxa, 1426, 27–50.
Dózsa-Farkas, K. (1997) Katalog der Enchytraeiden-Sammlung im Zoologischen Institut und Museum von Hamburg. Mitteilungen des hamburgischen zoologischen Museums und Instituts, 94, 35–47.
Dózsa-Farkas, K. (2000) Achaeta gigantea sp. n., a large-sized species of Enchytraeidae (Oligochaeta) from South Africa. Opuscula Zoologica. Budapest, 32, 81–85.
Dózsa-Farkas, K. & Boros, G. (2005) Achaeta antefolliculata sp.n., a new enchytraeid species (Oligochaeta, Enchytraeidae) from the rock grassland of the Sas-Hegy in Hungary. Acta Zoologica Academiae Scientiarum Hungaricae, 51, 279–285.
Envall, I., Källersjö, M. & Erséus, C. (2006) Molecular evidence for the non-monophyletic status of Naidinae (Annelida, Clitellata, Tubificidae). Molecular Phylogenetics and Evolution, 40, 570–584.
Ferretti, A.R. & de Britez, R.M. (2006) Ecological restoration, carbon sequestration and biodiversity conservation: The experience of the Society for Wildlife Research and Environmental Education (SPVS) in the Atlantic Rain Forest of Southern Brazil. Journal for Nature Conservation, 14, 249–259.
Graefe, U. (1989) Systematische Untersuchungen an der Gattung Achaeta (Enchytraeidae, Clitellata). 2. Beschreibung von vier neuen Arten. Mitteilungen des hamburgischen zoologischen Museums und Instituts, 86, 127–131.
Graefe, U. (2002) On the body architecture of the genus Achaeta (Enchytraeidae, Clitellata). Natura Jutlandica Occasional Papers, 2, 106.
Graefe, U. (2007) Achaeta diddeni sp. nov. (Enchytraeidae, Clitellata) from northern German lowlands. Folia Facultatis scientiarum naturalium Universitatis Masarykianae Brunensis, Biologia, 110, 35–40.
Graefe, U., Dózsa-Farkas, K. & Christensen, B. (2005) Achaeta unibulba sp. n., a widespread European species (Oligochaeta, Enchytraeidae). Proceedings of the Estonian Academy of Sciences: Biology, Ecology, 54, 271–278.
Healy, B. (1996) New species of Marionina (Oligochaeta: Enchytraeidae) from a wave-exposed rocky shore in SE Ireland. Journal of Natural History, 30, 1287–1295.
Höfer, H., Verhaagh, M. & Fabry, R. (2007) SOLOBIOMA - Bodenbiota und Biogeochemie in Küstenregenwäldern Südbrasiliens. Zeitschrift für Umweltchemie und Ökotoxikologie, 19, 128–131.
IBGE - Instituto Brasileiro de Geografás e Estadística (1992) Manual técnico da vegeatação brasileira (http://biblioteca.ibge.gov.br/). IBGE, Rio de Janeiro, 92 pp.
International Commission on Zoological Nomenclature (1999) International Code of Zoological Nomenclature. The International Trust for Zoological Nomenclature, London, 305 pp.
ISO International Standard Organization. (2006) Soil quality - Sampling of soil invertebrates - Part 3: Sampling and soil extraction of enchytraeids (ISO/FDIS 23611-3:2006(E)). Guideline prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 4, Biological methods,
Lasserre, P. (1968) Présence du genre Achaeta Vejdovsky, 1877 (Oligochaeta, Enchytraeidae) dans les plages sableuses marines. Description de Achaeta littoralis n. sp. Bulletin du Muséum National d'Histoire Naturelle, 2e Série, 39, 979–983.
Liebsch, D., Goldenberg, R. & Mendes Marques, M.C. (2007) Florística e estructura de comunidades vegetais em uma cronoseqüência de Floresta Atlântica no Estado do Paraná, Brasil. Acta botanica brasilica, 21, 983–992.
Michaelsen, W. (1889a) Synopsis der Enchytraeiden. Abhandlungen aus dem Gebiete der Naturwissenschaften, herausgegeben vom Naturwissenschaftlichen Verein in Hamburg, 11, 1–59.
Michaelsen, W. (1889b) Oligochaeten des Naturhistorischen Museums in Hamburg. I. Jahrbuch der Hamburgischen Wissenschaftlichen Anstalten, 6, 1–17.
Michaelsen, W. (1900) Oligochaeta. R. Friedländer, Berlin, 563 pp.
Michaelsen, W. (1903) Die geographische Verbreitung der Oligochaeten. R. Friedländer, Berlin, 187 pp.
Myers, N., Mittermeier, R.A., Mittermeier, C.G., da Fonseca, G.A.B. & Kent, J. (2000) Biodiversity hotspots for conservation priorities. Nature, 403, 853–858.
Nielsen, C.O. & Christensen, B. (1963) The Enchytraeidae. Critical revision and taxonomy of European species. Supplement 2. Natura Jutlandica, 10, 1–19.
Nielsen, C.O. & Christensen, B. (1961) The Enchytraeidae. Critical revision and taxonomy of European species. Supplement 1. Natura Jutlandica, 10, 1–23.
Nielsen, C.O. & Christensen, B. (1959) The Enchytraeidae. Critical revision and taxonomy of European species (Studies on Enchytraeidae VII). Natura Jutlandica, 8‑9, 1–160.
Nurminen, M. (1973) Enchytraeidae (Oligochaeta) from the vicinity of Montreal. Annales Zoologici Fennici, 10, 399–402.
Righi, G. (1974) Notas sobre os Oligochaeta, Enchytraeidae do Brasil. Papéis Avulsos de Zoologia. Museu de Zoologia da Universidade da São Paulo, 28, 127–145.
Righi, G. (1981) Notas sobre Enchytraeidae (Oligochaeta) Brasileiras. Revista Brasileira de Biologia. Rio de Janeiro, 41, 427–430.
Römbke, J. (2007) Enchytraeidae of tropical soils: State of the art, with special emphasis on Latin America. Folia Facultatis scientiarum naturalium Universitatis Masarykianae Brunensis, Biologia, 110 (in press).
Römbke, J. & Schmidt, M. (1999) REM documentation of putative cuticular sense organs of enchytraeids. In: Schmelz, R.M. & Sühlo, K. (Eds), Newsletter on Enchytraeidae No. 6. Proceedings of the 3rd International Symposium on Enchytraeidae, Osnabrück, Germany. Universitätsverlag Rasch, Osnabrück, Germany, pp. 15–20.
Römbke, J., Collado, R. & Schmelz, R.M. (in press) Abundance, distribution, and indicator potential of enchytraeid genera (Enchytraeidae, Clitellata) in secondary forests and pastures of the Mata Atlântica (Paraná, Brazil). (Proceedings of the 10th International Symposium on Aquatic Oligochaeta, 26–21 Oct. 2006, Wuhan, China). Acta Hydrobiologica Sinica.
Römbke, J., Collado, R. & Schmelz, R.M. (2005) Oligochaetes (Clitellata) of the Mata Atlântica (Parana, Brazil): first results of the SOLOBIOMA project. Proceedings of the Estonian Academy of Sciences: Biology, Ecology, 54, 302–309.
Rota, E. (1995) Italian Enchytraeidae (Oligochaeta). I. Bollettino di Zoologia, 62, 183–231.
Rota, E. & Erséus, C. (2003) New records of Grania (Clitellata, enchytraeidae) in the Northeast Atlantic (from Tromsø to the Canary Islands), with descriptions of seven new species. Sarsia, 88, 210–243.
Rota, E. & Healy, B. (1999) A taxonomic study of some Swedish Enchytraeidae (Oligochaeta), with descripions of four new species and notes on the genus Fridericia. Journal of Natural History, 33, 29–64.
Rota, E., de Eguileor, A. & Grimaldi, A. (1999) Ultrastructure of the head organ: a putative compund georeceptor in Grania (Annelida, Clitellata, Enchytraeidae). Italian Journal of Zoology, 66, 11–21.
Rota, E., Wang, H. & Erséus, C. (2007) The diverse Grania fauna (Clitellata: Enchytraeidae) of the Esperance area, Western Australia, with descriptions of two new species. Journal of Natural History, 41, 999–1023.
Schmelz, R.M. (2003) Taxonomy of Fridericia (Oligochaeta, Enchytraeidae). Revision of species with morphological and biochemical methods. Abhandlungen des Naturwissenschaftlichen Vereins in Hamburg (Neue Folge), 38, 415 + 73 fig.
Schmelz, R.M. & Collado, R. (2005) Achaeta becki sp. nov. (Oligochaeta: Enchytraeidae) from Amazonian forest soils. Zootaxa, 1084, 49–57.
Vejdovský, F. (1878) Zur Anatomie und Systematik der Enchytraeiden. Sitzungsbericht der Königlich Böhmischen Gesellschaft der Wissenschaften, 1877, 294–304.
Vejdovský, F. (1879) Beiträge zur vergleichenden Morphologie der Anneliden. I. Monographie der Enchytraeiden. Verlag von Friedrich Tempsky, Prag, 61 pp.
Vejdovský, F. (1884) System und Morphologie der Oligochaeten. Prag, 172 pp.
Yañez, E., Cuadrado, S. & Martínez-Ansemil, E. (2005) External sense organs in freshwater oligochaetes (Annelida, Clitellata) revealed by Scanning Electron Microscopy. Journal of Morphology, 267, 198–207.
Zicsi, A. & Csuzdi, C. (1991) Der erste Wiederfund von Zapotecia amecamecae Eisen, 1900 aus Mexico (Oligochaeta: Acanthodrilidae). Miscellanea Zoologica Hungarica, 6, 31–34.